the father of american sniper chris kyle , said he and wife deby were ` surviving ' now that they finally had time to process their death , following the end of his killer 's trial .
in february , routh was found guilty of the murders and sentenced to life in prison , in an emotionally-charged interview with nbc news .
the father of american sniper chris kyle and friend chad littlefield were shot dead at a texas gun range in 2013 by eddie routh , after taking the troubled vet to the range to help him cope with his ptsd .